Method and apparatus for detecting faults in transparent material

An apparatus for detecting faults in transparent material, said apparatus comprising

• a first radiation source for illumination of a definite partial volume of the transparent material,
• a detector for light originating from said partial volume;
• and
• a second radiation source arranged in relation to the transparent material so that an associated optical path extends exclusively in an interior of the transparent material;
• wherein said first radiation source comprises two parts emitting light of different intensities and wavelengths.

An apparatus for detecting faults in a transparent manufactured material to determine whether or not the transparent manufactured material meets specifications during quality control testing, said apparatus comprising

• a first pulsed light source arranged to illuminate a definite partial volume in an interior of the transparent manufactured material,
• a detector for light originating from said definite partial volume;
• a second pulsed light source arranged in relation to the transparent manufactured material so that an optical path of light from said second pulsed light source extends exclusively through the definite partial volume in the interior of the transparent manufactured material;
• and
• an electronic means for controlling said first pulsed light source and said second pulsed light source, so that said first pulsed light source emits light pulses exclusively in intervals between light pulses originating from said second pulsed light source wherein said first radiation source comprises two part emitting light of different intensities and wavelengths.

A method for detecting faults in a transparent manufactured material in order to ascertain whether or not the transparent manufactured material meets predetermined specifications during quality control testing, said method comprising the steps of;

• a) irradiating a definite partial volume entirely within an interior of the transparent manufactured material with a first radiation source;
• b) coupling light of a second radiation source into the transparent manufactured material so that an optical path of said light passes through said definite partial volume entirely within said interior of the transparent manufactured material;
• c) detecting scattered light from said fault in said partial volume, detecting bright field absorption from said fault in said partial volume and/or detecting deflection of light of said first radiation source by said fault in said partial volume in order to detect the presence of said fault in said partial volume of the transparent manufactured material;
• and
• d) determining a fault type of said fault from a ratio of a bright field signal to a scattered light signal or from a ratio of a deflection signal to said scattered light signal;
• e) providing an analyzing unit for processing detected signals from said definite partial volume, said detected signals including said scattered light signal and said detected signals also including said bright field signal and/or said deflection signal, in order to ascertain the type of said fault within said definite partial volume according to said ratio determined in step d);
• and
• f) outputting the type of said fault from said analyzing unit.